1. Field of the Invention
The present invention relates generally to processes for the fabrication of metal oxide semiconductors and more particularly to a process of making complementary metal oxide semiconductors in dielectrically isolated regions using a self-aligned gate.
2. Description of the Prior Art
In the field of semiconductor processes, many techniques are used for the formation of complementary metal oxide semiconductors. A major trend in the industry has been the use of the gate metal as a mask for the extension of previously formed source and drain regions to the edge of the gate and therefore form a self-aligned channel region. The extension of source and drain regions using the gate metal as a mask has been performed using ion implantation as well as open tube diffusion.
The processes of the prior art for the formation of complementary MOS devices involves lengthy expensive processing. Techniques now used in industry have not been able to provide the CMOS's with well controlled threshold levels while maintaining high packing density.